基于CORDIC算法的高速高精度NCO的FPGA设计

Design of FPGA for High Speed High Accuracy NCO Based on CORDIC Algorithm

介绍一种利用矢量旋转的CORDIC(Coordination Rotation DIgital Computer)算法,相比较传统NCO采用的查找表算法,证明查找表算法运算速度已不适用于高速宽带数字接收机以及扩频通信的应用,为了实现高速正交数字混频器中的数控振荡器(NCO),采用CORDIC算法产生正余弦信号的实现过程,给出采用ALTERA的stratix系列FPGA中设计数控振荡器的顶层设计结构以及仿真结果,证明基于此算法采用FPGA的可行性设计。

A coordination rotation digital computer （CORDIC） algorithm using vector rotation is provided. Comparing with look-up table algorithm used generally by traditional numeric controlled oscillator （NCO）, it is proved that low operating speed of look-up table algorithm can not meet requirement of highspeed wide-band digital receiver and spread-spectrum communication. In order to archive NCO used in high-speed quadrature digital mixer, generation process of sine and cosine signals by using of CORDIC algorithm is presented; and top-layer circuit structure designed with Stratix series of field programmable gate arrays （FPGAs） manufactured by ALTERA company is given. Simulation results show feasibility of the design by way of the CORDIC algorithm and FPGAs.